1. Field of the Invention
The present invention relates to a wake-up controller and a method for performing a wake-up control for a peripheral circuit such as a transmitter/receiver circuit.
2. Description of the Background Art
It is expected that a radio communication device carried on a mobile system is operated with low power consumption, which is especially more required for a battery-operated radio communication device. When a frame signal for a radio communication service comprises a time slot corresponding to a header carrying information such as synchronous control, an identification and a service content, and two slots for containing data, it is operated comprehensively with low power consumption by a wake-up control method such that a mobile system is powered on or off in response to a result of detecting a signal in a radio frequency (RF) band. Japanese Patent Laid-Open Publication No. 2005-80205 discloses a transponder, as a radio communication device, which communicates on microwave with an interrogator, and is enabled to communicate with the interrogator by powering on the transponder only when the transponder receives a peculiar start command transmitted from the interrogator and matching a criterion command to decide.
However, when a radio communication device senses other service signals therearound in the same high-frequency band as the device, it may be erroneously operative in wake-up control due to the other service signals. This malfunction may power on the mobile system unnecessarily, thus being a bar to low power consumption. Under the circumstances, especially, a non-contact type of battery-powered mobile communication system comprising semiconductor integrated circuits tends to start the circuits frequently, thereby burning more battery power to shorten its battery run time.